Sensitized photographic emulsions containing quaternary ammonium compounds



United States Patent New Jersey N0 Drawing. Filed Sept. 11, 1961, Ser. No. 137,035 9 Claims. (Cl. 96-107) This invention relates to photographic emulsions, and, more particularly, photographic emulsions of the silver halide type. It is known that the inherent sensitivity of photographic silver halide emulsions (whether spectrally sensitized or not) can be increased, and there has been constant effort to produce higher and higher speeds in photographic emulsions. For example, it is known that the speed of gelatino silver halide emulsions can be enhanced by an extended digestion or ripening of the emulsion. It is also known that the speed of silver halide emulsions (spectrally sensitized or not) can be enhanced by incorporating into the emulsions compounds containing an atom of the sulfur group directly joined by a double bond to a single metalloid atom to which is attached another group of atoms; for example, allyl isothiocyanate and allyl thiourea.

More recently, it has been found that the speed of photographic silver halide emulsions (Whether spectrally sensitized or not) can be increased by incorporating in the emulsions a cationic surface active substance of the quaternary ammonium type. The speed increases thus obtainable are ordinarily complementary to the speeds obtainable by the prior methods. Many of the more active sensitizers, particularly of the quaternary ammonium type, have been double enders; that is they must contain two of the requisite quaternary ammonium functions in order to obtain reasonably high activity. 7

A difficulty encountered with several sensitizers is that the substances used to sensitize the emulsion appear to diffuse to a greater or less extent from the emulsions with the result that their effect upon the photographic emulsion may be decreased.

One object of my invention is to provide photographic emulsions chemically sensitized with quaternary ammonium compounds; another object is to provide quaternary ammonium compounds which diffuse, if any, only to a small extent into the film base upon which the emulsion is coated. Other objects of my invention will appear herein. 7

We have found that compounds useful for chemically sensitizing silver halide emulsions can be represented by the general formula:

romcnononnimxwhere Y is an al l mercapto group of 6-30 carbon atoms wherein Z is alkylene dimercapto or alkylene diamino, the chain connecting the end S or N being either straight aliice phatic carbon chain or an aliphatic hetero chain, but in either case of at least 4 carbon atoms. These compounds are employed as sensitizers in photographic emulsions in concentrations therein not more than 4 g. per g. mole of silver halide in the photographic emulsion. In most instances, a satisfactory concentration of sensitizer is found between .2 g. and 3 g. per g. mole of silver halide. Compositions in accordance with the invention are prepared by adding to an ordinary aqueous silver halide emulsion, with or without other sensitization, the desired amount of the sensitizing material, such as in solution or suspension in water.

The preparation of sensitizers in accordance with my invention is conveniently carried out in excellent yield by reacting a quaternary ammonium epoxide with an appro-' priate amine or mercaptan. Some amines which are useful in preparing compounds in accordance with my invention are those having formulas such as Alkyl substituted amines such as C H NHCH may also be employed. Some mercaptans which are useful for reacting with a quaternary ammonium expoxide to give sensitizers useful in my invention are C H SH, C H SH, C H SH and C H SH. If desired, amines or mercaptans having greater numbers of carbon atoms also show useful properties for sensitizing silver halide photographic emulsions.

In the preparation of his compounds useful as sensitizers dimercapto compounds suitable for reacting with quaternary ammonium epoxides to prepare sensitizers are for for example:

and the like.

Examples of diamino compounds suitable for reacting with quaternary ammonium epoxides to prepare sensitizers are: I

z 2 iz -z z 2) iu z CH NH CH NHCH and the like.

Some of the quaternary ammonium epoxides which may be reacted to form sensitizers in accordance with my invention are: 2,3-epoxypropyltrimethylammonium ptoluenesulfonate, 2,3-epoxypropyldimethylpropylammonium p-toluenesulfonate, 2,3-epoxypropyldiethylmethyl ptoluenesulfonate.

The preparation of sensitizing compounds of the monoquaternary ammonium type for use in compositions in accordance with my invention is conveniently carried out in excellent yield by the reaction of a quaternary ammonium epoxide with an amine or mercaptan in accordance with the following equations:

R" RNHR+ CH -CHCH NR -X- RNCH CH0HCH NR3-X R being alkyl groups of 1-4 carbon atoms, R being alkyls as of C -C (mercaptan) or C -C (amine), R" being either hydrogen or alkyl of 1-4 carbon atoms and X being anysuitable anion such as p-toluenesulfonate, per- 7 7 chlorate or the like.

For the preparation of sensitizing compounds of the bisquaternary ammonium type the dimercaptan or diamine is reacted with the quaternary ammonium epoxide to result in a compound having the formula V nmomononomzomon01301121 13922:-

EXAMPLE 1 p 80' g. of 3-dimethylamino 1,2-epoxypropane prepared by the method described by Gilman and Fullhart, IACS 71, 1430 (1949), in solution in 600 ml. of dry benzene was mixed with 150 g: of methyl p-toluenesulfonate over a. -minute period at 3035 C. lowedto stand at C. overnight whereupon it was filteredand recrystallized from acetone to given 189 g. of colorless plate-formed crystals. 11.5 g. of the epoxypropyltrimethylarnmonium p-toluenesulfonate thus prepared was dissolved in 25 m1. of methanol which was added to a solution consisting of 14.8 g. of dodecylamine in 25 ml. of methanol. While the addition was taking place over a half-hour period, the mass was stirred and heated to45 C; It was then maintained at this temperature with stirring for 18 hours. The solvent was removed, the product was stirred with ether and filtered. Recrystallization from acetonitrile gave 13.8 g. .of colorless crystals of 3-n-dodecylamino-Z-hydroxypropyl trimethylammonium p-toluenesulfonate. V g p Similar preparations were carried out of a number of similar compounds in like fashion, which compounds were separated out and analyzed. The compounds prepared, their yield, the melting points and formulas of the finished product are listed in the following table:

Quazernary salts,

. YCH CHOHCHiN(CHM-0 117809 from reaction of 2,S-poxypropyltrimethylammolzium p-tosylate with amines and mercapmns The following e xample illustrates sensitizing of emulsions with sensitizers of the type listedabove: 5 V

EXAMPLE 2 V The compounds referred to in the preceding table were.

added in'the amounts indicated in the following table to 'a high'speed silver brornoiodide gelatino emulsion. The respective emulsions were *coated onto a cellulose ace tate support. A sample of each coating was exposed on an Eastman 1B sensitometer and were then processed 'for 5 minutes in Kodak Developer DK50, fixed. washed and dried with the following results:

The mixture was :11:

Compound g [Ag mole Relative 'y i Fog.

speed Control 100 1. 02 .15

CMHNNHZ 15 11s 0. 1s

C14H20NH2 75 209 0. 84 29 CMHMNHQ- 3.0 240 0.05 ".42

CHHnNE .75 200 0.05 i .20

p i 214 0.05 .22 r 204 0.03 .24

omfizisnfluu 3. 0 100 0. s3 57 0.515011 .15 155 0.95 V .17' 0 1115811 r .75 102 0. 07 F .39 Carmen"-.. I 0.0 200 0.72' .01

cmH NHL 15 0. 9s 12 V p .75 150 0.92 .14 cwmlum 3.0 100 0.90 20 C1zH25NH2 15 132 0. 94

012112511111 .75 224 0.07 .25 CmHHNHZ 3. 0 289 0.81 4s ccHissH 15 107 1. 05 12 C6H13SH- 75 1. 07 11 081111011 15 120 0. 99 .12 (5 1111811- .75 135 0.91 i .12; CHuSH 0. 0 159 0. 94 .10 00110101-; -Q 100 1.20 14.

omrrfisH .15 151 v 1.11 .15 00110521-- a 174 1. 01 V 17 CuHzaSH .75 200 0. 9s .00 1115.9. .75 102 0.99 .10

bis A 3.0 1.02 .20

bis B .75 182 0. 95 .20 bisB 3.0 102 V 0.09 .20

The designation under the heading Compound refers. to the mercapto or amino compound which was reacted with the quaternary ammonium epoxide to form the sensitizer used. The designation bis* refers to nstonp coNmcn HCo(cH srr which was used to prepare a bisquaternary ammonium sensitizer which was prepared as the perchlorate salt having theempirical formula C34Hq2C1zN4012S2. Thedesignation bis A refers to (HSCH CHQ S, the bisquater-. 'nary ammonium sensitizer resulting therefrom having the empirical formula'C H N O S The designation bis B refers to the dimercaptan HS(CH SH from which the bisquaternary arnmoniumsensitizer having the em--, p1r1cal formula C H N O S -2H O was prepared. ll: 1 was'these resulting sensitizers which were used-in obtainmaterial designated con- 1y processed, etc., to the emulsions of the invention eX- cept that the sensitizer referred to was not embodied therein.

The invention is useful for the sensitizing of various types of emulsions, which emulsions may or may not include various addenda. Some of the types of addenda which may be present in emulsions sensitized in accordance with our invention are the following:

(1) OPTICAL SENSITIZERS If desired, the emulsions can be optically sensitized with cyanine or mercocyanine dyes such as those described in any of the following patents: U.S. Patents Nos. 1,846,301, 1,846,302 and 1,942,854 of Brooker; U.S. Patent No. 1,990,507 of White; U.S. Patents Nos. 2,112,140, 2,165,- 338, 2,493,747 and 2,739,964 of Brooker and White; U.S. Patent No. 2,493,748 of Brooker and Keyes; U.S. Patents Nos. 2,503,776 and 2,519,001 of Sprague; U.S. Patent No. 2,666,761 of Heseltine and Brooker; U.S. Patent No. 2,734,900 of Heseltine; U.S. Patent No. 2,739,149 of Van Lare; and British Patent 450,958 of Kodak Limited.

(2) STABILIZERS 2,743,181 of Allen and Reynolds, U.S. Patent No. 2,716,- 7

062 of Carroll and Beach, U.S. Patent No. 2,735,769 of Allen and Beilfuss, U.S. Patent No. 2,756,147 of Reynolds and Sagal, U.S. Patent No. 2,772,164 of Allen and Sagura or those referred to in the article by Birr in Z. wiss Pho volume 47, 1952, pp. 2-28; disulfides as disclosed in Belgian Patent No. 596,317; quaternary benzothiazolium compounds as listed in U.S. Patent No. 2,131,038 of Brooker and Stand; polymethylene bis-benzothiazolium salts as disclosed in U.S. Patent No. 2,694,- 716 of Allen and Wilson; zinc and cadmium salts as disclosed in U.S. Patent No. 2,839,405 of Jones; or a carboxymethylmercapto compound as disclosed in U.S. Patent No. 2,819,965 of Murray, Reynolds and Van Allan.

(3) GELATIN PUASTICIZERS Glycerin; dihydroxy alkanes such as 1,5-pentane diol as described in U.S. Patent No. 2,960,404 of Milton and Murray; esters of ethylene bis-glycolic acids such as ethylene bis-(methylglycolate) as described in U.S. Patent No. 2,904,434 of Milton; bis(ethoxy diethylene glycol) succinate as described in U.S. Patent No. 2,940,854 of Gray; or a polymeric hydrosol as results from the emulsion polymerization of a mixture of an amide or an acid of the acrylic acid series, an acrylic acid ester and a styrene-type compound as described in U.S. Patent No. 2,852,386 of Tong.

( 4) HARDENERS Formaldehyde; a halogen-substituted aliphatic acid such as mucobromic acid as described in U.S. Patent No. 1,080,019 of White; a compound having a plurality of acid anhydride groups or a dicarboxylic or a disulfonic acid chloride as described in U.S. Patents Nos. 2,725,294 and 2,725,295 of Allen and Carroll; a cyclic 1,2-diketone as described in U.S. Patent No. 2,725,305 of Allen and Byers; a bisester of methanesulfonic acid such as 1,2- di-(methane-sulfonoxy)-ethane as described in U.S. Patent No. 2,726,162 of Allen and Laakso; 1,3-dihydroxymethylbenzimidazol-Z-one as described in U.S. Patent No. 2,723,316; a dialdehyde as described in application Serial No. 18,471, and now abandoned, of Allen and Burness;

6 a bis-aziridine compound as described in U.S. Patent No. 2,950,197 of Allen and Webster; a 2,3-dihydroxy dioxane as described in U.S. Patent No. 2,870,013 of Jefi'reys; or a diisocyanate as described in application Serial No. 805 357 and now Patent No. 3,103,437 of Henn et a1.

(5) COATING AIDS Saponin; an acylated alkyl taurine as described in U.S. Patent No. 2,739,891; a Water-soluble maleopimarate as described in U.S. Patent No, 2,823,123; or an alkali metal salt of a substituted amino acid as described in Knox and Wilson application Serial No. 600,679 and now Patent No. 3,038,804.

The addenda which we have described may be used in various kinds of photographic emulsions such as X- ray or other non-optically sensitized emulsions or in orthochromatic, panchromatic or infrared sensitive emulsions. They may be added to the emulsion before or after sensitizing dyes have been provided. Various silver salts may be used as the light-sensitive salts in the emulsion, such as silver bromide, silver iodide, silver chloride or mixed silver halides such as silver bromochloride or silver bromoiodide. The agents may be used in emulsions intended for color photography, for example emulsions containing color-forming couplers or emulsions to be developed by solutions containing couplers or other color-generating materials. Emulsions of the mixed packet type as described in U.S. Patent No. 2,698,794 or emulsions of the mixed grain type as described in U.S. Patent No. 2,592,243 may be sensitized in accordance with the invention. The sensitizers of the invention may be used in emulsions for color purposes having incorporated couplers with reversal as well as direct color development.

I claim:

1. A silver halide photographic emulsion containing therein, per mole of silver halide, 0.1 to 4 g. of a sensitizer selected from the group consisting of the com pounds having the formula YCH CHoHCHgNRaX wherein Y is selected from the group consisting of alkyl mercapto groups of 6-30 carbon atoms and secondary and tertiary amino groups containing linear chains of 10-30 carbon atoms, R is lower alkyl of 1-4 carbon atoms and X is a suitable anion and the compounds having the formula RaNCH CHOHCHgZCHgCHOHCHglG'RrZX wherein R is lower alkyl of 1-4 carbon atoms, X is a suitable anion and Z is selected from the group consisting of dimercapto and diamino groups in which the mercapto and the amino groups are joined by an alkylene chain containing at least 4 carbon atoms and dirnercapto and diamino groups in which the mercapto and the amino groups are joined by an aliphatic chain of hetero atoms including at least 4 carbon atoms.

2. A silver halide photographic emulsion containing, per mole of silver halide, 0.1 to 4 g. of a sensitizer having the formula Yongononcrnimaxwherein Y is a secondary amine group, having the formula C H NH, R is lower alkyl of l-4 carbon atoms and X is a suitable anion.

3. A silver halide photographic emulsion containing, per mole of silver halide, 0.1 to 4 g. of a sensitizer having the formula wherein Y is a secondary amine group having the formula C H NH, R is alkyl of 1-4 carbon atoms and X is a suitable anion.

4. A silver halide photographic emulsion containing,

' ing the formula 7 7 per mole of silver halide, 0.1 t04 g. of a sensitizer having the formula V v i YCHgCHOHCHiNRaX wherein Y is an alkyl mercapto group having the formula C3H17s, R is alkyl off 1-4 carbon atoms and X is a suitable anion.

'5. A silver halide photographic emulsion containing, per mole of silver halide, 0.1 to 4 g. of a sensitizer'hav- Yonzononomfirmxk 8 in which Z is a 5 7 S (CH 5CONH (CH i NHCO (CH2)' S R is alkyl of 1-4 carbon atoms and Xis a suitable anion.

7 8. A silver halide photographic emulsion containing,

therein," per mole of silver halide, 0.1'to 4 g. of'a sensitizer having the formula J ml 'ronaononongzonronononzfin -zxin which Z is '-S(CH SV, R is alkyl of -14 carbon atoms, and X is a'suitable anion. r

9. A silver halide photographic emulsion containing therein, per mole ofsilverhalide, 0.1 to 4 g; offase'nsitizer having the formula.v 1 R510nzononcrnzomcno'ncnzfimzxe j in'which Z issSCH CH SCH CH S', R is alkyl on carbon atoms and X is a suitable anion.

References Cited by the Examiner UNITED STATES PATENTS 2,940,851 V 6/40 Beavers ct al. V V V.V 96- 107 3,038,805 6/62 Dann' et al. 9s 107 NORMAN GJTORCHIN, l 'rimizryrExwm'iner. 

1. A SILVER HALIDE PHOTOGRAPHIC EMULSION CONTAINING THEREIN, PER MOLE OF SILVER HALIDE, 0.1 TO 4 G. OF A SENSITIZER SELECTED FROM THE GROUP CONSISTING OF THE COMPOUNDS HAVING THE FORMULA 